Overload release coupling



OVERLOAD RELEASE COUPLING F' iled Aug. 6, 1947 FIG. I 7 2 l .wz FIG W /0 I: /2 I 9 I 5 INVENTOR 3? f5 /3 NED J. REES ATTORNEY Patented Oct. 14, 1952 OVERLOAD RELEASE COUPLING Ned J. Rees, St. Louis, Mo., assignor to James R.

Kearney Corporation, St. Louis, Mo., a corporation of Missouri Application August 6, 1947, Serial No. 766,564.

2 Claims.

This invention relates generally to insulated electrical tools adapted for use in applying clamps, and other devices, to energized electrical conductors, and more specifically to such a tool which is in the form of an elongated stick and is employed to manipulate screwthreaded adjusting elements of clamps, and other devices, in applying said clamps or other devices to, or removing same from, overhead, energized electrical conductors, the predominant object of the invention being to provide an insulated tool of the type referred to which includes as part thereof a torque-limiting means that serves to prevent a user of the tool from applying excessive torque to the screwthreaded adjusting elements of clamps, or other devices, which are being applied to overhead, energized electrical conductors with the aid of the tool.

Prior to this invention, considerable trouble has been experienced because of the tendency of lineman to tighten clamps beyond the elastic limits of the materials of which the clamps are made. The usual result of this situation is that the adjusting screws of the clamps are compressed thereby changing the pitch of the screwthreads of said adjusting screws and making it extremely difficult to remove the clamps from the conductors to which they are applied. In the use of the tool of the present invention this situation is completely eliminated in that the tool disclosed herein is provided with torque-limiting means which forms a part thereof and which prevents more than a predetermined degree of torque being applied to the adjusting screw of a clamp, or other device, in applying such clamp, or other device, to an electrical conductor.

Fig. 1 is a side elevation of the improved tool of the present invention, parts of the pole of the tool being broken away.

Fig. 2 is a fragmentary section taken on line" 2--2 of Fig. 1.

Fig. 3 is a horizontal section taken on line 33 of Fig. 2.

Fig. 4 is a horizontal-section taken on line 4-4 of Fig. 2.

In the drawing, wherein is shown for purposes of illustration, merely, one embodiment of the invention, A designates the improved tool generally. The tool A includes a pair of elongated pole members I and 2 that are preferably formed of suitable. wood treated to impart to said. wood the maximum electrical insulating properties of which it is capable. Mounted on the pole member l at the outer end thereof is a socket element 3' which receives therein an end portion of saidpole memberl, said socket elementbeing provided with an opening 4 that is shaped to receive the eye of a screwthreaded adjusting element of a clamp, or other device, for rotating said adjusting element.

Mounted on the pole member I at the end thereof opposite to the end at which the socket elements 3 is disposed is a tubular member 5, an end portion of the pole member I being extended into said tubular member 5, and a rivet 6, which extends through apertures formed through said pole member I and through opposed wall portions of said tubular element '5, serves to secure said tubular element to said pole member.

In like manner, the pole 2 has mounted thereon a tubular member 1 which is similar to the tubular member 5 except that said tubular member I is of slightly greater length than the tubular member 5. An end portion of the pole member 2 extends into the tubular member 1, as is shown to good advantage in Fig. 2, and a rivet 8, which passes through apertures formed through the pole member 2 and opposed portions of the wall of the tubular member I, serves to secure said tubular member to said pole member. The tubular member 5 and a substantial portion of the tubular member 1 are embraced by an elongated, outer sleeve 9, said outer sleeve being secured to the pole member I and the tubular member 5 by the rivet 6 previously referred to herein.

Mounted within the lower portion of the tubular member 5, as shown in Fig. 2, is a ratchet disk l0, said ratchet disk having annularly arrangedratchet teeth ll formed at the lower face thereof. Also, the ratchet disk ID has formed therethrough a centrally located opening 12, said opening preferably being of non-circular shape. The ratchet disk I0 is secured to the tubular member 5 by a plurality of pins I3 which are disposed in apertures formed. in the said tubular member 5 and said ratchet disk H]. In like manner, the tubular member I has mounted within the upper portion thereof a ratchet'disk l4 similar to the ratchet disk Ill, said ratchet disk l4 having annularly arranged ratchet teeth l5 formed at the upper face thereof. Also the ratchet disk [4 has formed therethrough a centrally located opening [6 which is alined with the opening l2 of the ratchet disk ill but which is by preference of circular shape. The ratchet disk [4 is secured to the tubular member 1 by a plurality of pins II which are disposed in apertures formed in said tubular member I and said ratchet disk M.

The pole members I and 2, and the partsassociated therewith, are connected together for rela-- tive longitudinal, yielding movement-by abolt l8 whose head contacts with the upper face of the ratchet disk It] and whose shank extends through the openings 12 and N of the ratchet disks l0 and I 4, the shank of said bolt having a noncircular portion immediately adjacent to the head of said bolt which is disposed in the correspondingly shaped central opening of the ratchet disk In so as to prevent relative rotation of the bolt shank and said ratchet disk It. At the extreme lower end portion of the shank of the bolt IS a nut and washer assembly I9 is mounted on said bolt shank, and interposed between the washer of said nut and washer assembly and the lower face of the ratchet disk 14, in embracing relation with respect to said bolt shank, is a coil spring 20. The coil spring is maintained in place under compression and as a result thereof the ratchet teeth of the ratchet disks [0 and M are drawn into close, meshing relation, as is shown in Fig. 2.

In the use of the improved tool disclosed herein in applying a clamp, for instance, to an overhead electrical conductor, the eye of the screwthreaded adjusting element of the clamp is caused to extend into the opening d of the socket element 3 and the tool is rotated about its axis so as to correspondingly rotate the screwthreaded adjusting element of the clamp and thereby cause the jaws of the clamp to grip the electrical conductor to which the clamp is being applied. The force exerted by the coil spring 20 is sufficient to cause the ratchet teeth of the ratchet disks It and M to remain in mesh under ordinary circumstances and therefore the rotation imparted to the lower pole member 2 by the operator will be transmitted by the meshing ratchet teeth to the upper pole member 1. However, if, when the clamp has been applied to the overhead conductor, the operator attempts to impart additional and excessive torque to the adjusting element of the clamp with the aid of the tool A, the resistance to rotation set up in the upper portion of the tool will cause the coil spring 28 to yield with the result that the lower portion of the tool will rotate with respect to the upper tool portion, the ratchet teeth of the ratchet disk l4 sliding idly by the ratchet teeth of the ratchet disk ID and imparting no rotation thereto.

An important feature of the invention is that the force exerted by the coil spring 20 may be regulated by adjusting the nut of the nut and washer assembly [9 longitudinally of the shank of the bolt [8. Also, it is to be noted that the torque-limiting action of the tool of the present invention is effective only when the tool is rotated about its axis in a right-hand manner, as when applying a clamp having an adjusting element provided with right-hand screwthreads. As a result of this situation there is no limitation of torque in the use of the tool when a clamp is being removed from an overhead conductor and where, because of corrosion of parts of the clamp, very considerable torque is required to release the clamp from the conductor.

I claim:

1. A tool for applying devices to overhead electrical conductors comprising a pair of axially alined pole members, tubular elements secured to said pole members at adjacent ends thereof, ratchet disks supported by said tubular elements and having ratchet teeth which mesh to mechanically connect said ratchet disks together whereby axial rotation of one of said pole members is transmitted to the other of said pole members through said interengaged ratchet disks,

a bolt having a head which engages one of said ratchet disks and having a shank which extends through apertures formed through said ratchet disks, a coil spring embracing said bolt shank, an abutment mounted for adjustment on said bolt shank, said coil spring being interposed under compression between said abutment and one of said ratchet disks whereby the ratchet teeth of said ratchet disks are normally forced into meshing engagement, and said coil spring being adapted to yield under excessive torque is applied to the tool so as to permit relative rotation of said ratchet disks and the pole members to which they are related, and an outer sleeve which embraces portions at least of said tubular elements and is secured to one of said pole members, said ratchet teeth being so shaped that said coil spring yields when excessive torque is applied to the tool to permit relative rotation of said ratchet disks when the tool is rotated in one direction only, the ratchet disks remaining in engagement when the tool is rotated in the opposite direction to apply excessive torque to the tool.

2. A tool for applying devices to overhead electrical conductors comprising a pair of axially alined pole members, tubular elements secured to said pole members at adjacent ends thereof, ratchet disks supported by said tubular elements and having ratchet teeth which mesh to mechanically connect said ratchet disks together whereby axial rotation of one of said pole members is transmitted to the other of said pole members through said interengaged ratchet disks, a bolt having a head which engages one of said ratchet disks and having a shank which extends through apertures formed through said ratchet disks, a coil spring embracing said bolt shank, an abutment mounted for adjustment on said bolt shank, said abutment comprising a washer of a nut and washer assembly, said coil spring being interposed under compression between said abutment and one of said ratchet disks whereby the ratchet teeth of said ratchet disks are normally forced into meshing engagement, and said coil spring being adapted to yield when excessive torque is applied to the tool so as to permit relative rotation of said ratchet disks and the pole members to which they are related, and an outer sleeve which embraces portions at least of said tubular elements and is secured to one of said pole members, said ratchet teeth being so shaped that said coil spring yields when excessive torque is applied to the tool to permit relative rotation of said ratchet disks when the tool is rotated in one direction only, the ratchet disks remaining in engagement when the tool is rotated in the opposite direction to apply excessive torque to the tool.

NED J. REES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,463,497 Bugatti July 31, 1923 1,843,875 Kendall et al. Feb. 2, 1932 FOREIGN PATENTS Number Country Date 652,350 France 1928 

